It has been said that the plumber is the safe guard of the health of a nation. This is evidenced by the fact that the major reason for the decrease in infectious disease in more technologically advanced civilizations is the presence of adequate plumbing, sewage and drainage systems. .While the benefits of modern plumbing are without dispute, such systems require periodic maintenance and cleaning to retain their proper operation.
Sewers, drains and other underground lines are particularly prone to clogging by sewage effluents or by penetration of tree roots and the like thereinto. Such obstructions can decrease the flow of liquid through the line resulting in loss of drain function and a back-up of sewage or waste water into a dwelling place. Because of the tendency of such drain lines to clog, it is necessary to periodically employ cleaning apparatus to remove the obstructions. The most commonly employed type of drain cleaner is a rotary cleaning apparatus comprised of a base having a motor mounted thereupon and adapted to rotate and advance a springlike cable or snake through the drain line. Generally the cable is fitted with a cutting head having one or more sharpened blades thereupon and adapted to sever and/or macerate any obstruction in the line. Such apparatus are well known to those of skill in the art and sold by a variety of manufacturers as for example the Ridge Tool Company of Elyria, OH.
Presently, polymeric drain line is enjoying ever increasing use both for sewage handling and for subsurface drain lines. Such drain lines are fabricated from durable polymeric materials such as polyvinyl chloride, (PVC); acrylonitrile butadiene styrene copolymer, ABS; high density polyethylene and similar materials. Such plastic drain lines offer advantages over heretofore employed metallic or ceramic lines insofar as the material is relatively light, easy to cut and fasten and not prone to corrosion damage.
While polymeric drain lines confer many advantages, problems occur when attempts are made to clean such lines with heretofore employed drain cleaning tools. Previous to the present invention cutters for rotary drain cleaners and snakes used to drive such cutters were fabricated from steel and tended to damage polymeric drain lines. In some instances, metallic drain cleaning tools can actually pierce a polymeric drain line resulting in a potential health hazard as well as necessitating a costly repair. In other instances, damage done by metallic cleaning tools can be more insidious. Such tools are capable of gouging or scraping the interior surface of a polymeric drain line so as to cause a weak spot subject to later failure or they may create a roughened or scarred surface which is prone to the collection of debris and the subsequent formation of a stoppage.
Accordingly, it will be appreciated that there is a need for drain cleaning apparatus adapted to reliably and safely clean polymeric drain lines without causing damage thereto. It is further desirable that any such equipment be compatible with heretofore available rotary drain cleaning apparatus.
U.S. Pat. No. 3,195,548 discloses a generally polymeric sewer opener configured as a flexible, preferably water carrying hose having a guide head thereupon fabricated from a number of plastic spheres. The sewer pipe opener of the '548 patent is not adapted to be used with a rotary sewer cleaning apparatus and is not capable of either penetrating long distances through an underground line or cutting its way through debris.
Accordingly there is a need for a sewer or drain cleaning apparatus which can be used with conventional cleaning equipment, and which can be rotatably advanced along lengths of drain lines, particularly polymeric drain lines, without causing any damage thereto. According to the present invention there is provided a cutter which may be employed with heretofore available rotary drain cleaning apparatus, which cutter is not capable of damaging polymeric drain lines. These and other advantages of the present invention will be apparent from the drawings, description and discussion which follow.